Economic aspects of the SMARThome systems

How much does a smart home system cost?

One of the most important criteria considered in the investment stage are, besides functionality, the ECONOMY of use. Investors usually only look at the construction budget forgetting the costs of future use of the system. In case of a smart home system it is worth it to integrate the lighting and heating. This requires only comparably small additional expenses.

Savings arising out of lighting control

In office buildings the savings provided by 'intelligent' light control are about 50-65%, and the costs of equipment purchased to provide these is returned after 3-4 years. In houses and apartments lighting besides its practical function also finds decorative uses and brings comfort - one will use a single group of lamps for 30-50 sq m of office spaces (which are switched together), and comparable residential space requires the use from one to even over a dozen different lighting circuits. These are factor that are so individual that it would not be proper to point to real world savings, even though they are there.

Savings arising out of heating control

Heating only when required. Thanks to independent temperature adjustment for every room one can save large amounts of energy (over 30%). A part of the rooms in the house is used only sporadically, thus they can be kept at a lower temperature; most rooms are only used a few hours a day (when returning from work and on weekends). In a typical installation they cause thus great losses of energy due to unneeded heating.

Period of return of investment

The calculations below were executed for three rooms of different capacity: bedroom, study and an open space (i. e. a living room with a corridor, kitchen and dining room). First, energy use and costs of typical heating were calculated for every room. The costs of KNX/EIB devices required to control the heating were also given (difference between the value of equipment controlling the heating and lighting, and the value of equipment controlling only the lighting). Below is a calculation of the depreciation:

Bedroom 17,58m2

Study 26,52m2

Open space 109,35m2

Yearly energy requirement in kW

5516

6058

15282

Energy costs

180 EUR

197 EUR

497 EUR

Savings in %

33,8 %

40,4 %

35,4 %

Savings annually

242,37

318,17

703,28

Equipment value

233 EUR

295 EUR

353 EUR

Linear depreciation period

3,85 yrs

3,71 yrs

2,01 yrs

Dynamic depreciation period(rate = 5%)

4,26 yrs

4,16 yrs

2,14 yrs

Depreciation takes place faster in case of larger rooms. This arises out of comparable value of control units for large and small rooms. The use of temperature control allows to eliminate 1/3 of the costs. At rising energy costs and falling interest rates, the depreciation period may be slower and future profits higher.